class User {
    private String account;
    private String password;
    private String email;

    // 构造函数
    public User(String acct, String pwd, String eml) {
        this.account = acct;
        this.password = pwd;
        this.email = (eml != null && !eml.isEmpty()) ? eml : "";
    }

    public User(String acct, String pwd) {
        this(acct, pwd, "");
    }

    public void displayInfo() {
        System.out.println("账号: " + account);
        System.out.println("密码: " + password);
        if (!email.isEmpty()) {
            System.out.println("邮箱: " + email);
        } else {
            System.out.println("邮箱: 未设置");
        }
    }

    public static void main(String[] args) {
        // 创建User对象
        User user1 = new User("嘉嘉", "111222", "jaja123@google.com");
        User user2 = new User("Amiya", "230831");

        System.out.println("User 1 information:");
        user1.displayInfo();

        System.out.println("\nUser 2 information:");
        user2.displayInfo();
    }
}